Chapter 24 Terms Of _Inquiry Into Life_

Front 1

DNA

Back 1

nucleic acid found in cells; the genetic material that specifies protein synthesis in cells

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purines

Back 2

type of nitrogen-containing base, such as adenine and guanine, having a double-ring structure

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pyrimidines

Back 3

type of nitrogen-containing base, such as sytosine, thymind, and uracil, having a single-ring base

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double helix

Back 4

double spiral; describes the three-dimensional shape of DNA

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complimentary base pairing

Back 5

hydrogen bonding between particular bases; in DNA, thymind (T) pairs with adenine (A), and guanine (G) pairs with cytosine (C); in RNA, uracil (U) pairs with A, and G pairs with C

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DNA replication

Back 6

synthesis of a new DNA double helix prior to mitosis and meiosis in eukaryotic cells and during prokaryotic fission in prokaryotic cells

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gene

Back 7

unit of heredity existing as alleles on the chromosomes; in diploid organisms, typically two alleles are inherited-one from each parent

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mRNA

Back 8

ribonucleic acid whose sequence of codons specifies the sequence of amino acids during protein synthesis

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RNA

Back 9

nucleic acid produced from covalent bonding of nucleotide monomers that contain the sugar ribose, occurs in three forms: messenger RNA, ribosomal RNA< and transfer RNA

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rRNA

Back 10

type of RNA found in ribosomes where protein synthesis occurs

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tRNA

Back 11

type of RNA that transfers a particular amino acid to a ribosome during protein synthesis; at one end, it binds to the amino acid, and at the other end, it has an anticodon that binds to an mRNA codon

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transcription

Back 12

process resulting in the productionof a strand of mRNA that is complementary to a segment of DNA

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translation

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process by which the sequence of codons in mRNA dictates the sequence of amino acids in a polypeptide

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RNA polymerase

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during transcription, an enzyme that joins nucleotides complementary to a portion of DNA

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promoter

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in an operon, a sequence of DNA where RNA polymerase bidns prior to transcription

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triplet code

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during gene expression, each sequence of three nucleotide bases stands for a particular amino acid

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codon

Back 17

three-base sequence in messenger RNA that causes the insertion of a particular amino acid into a protein or termination of translation

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anticodon

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three-base sequence in a transfer RNA molecule that pairs with a complementary codon in mRNA

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ribosome

Back 19

RNA and protein in two subunits; site of protein synthesis in the cytoplasm

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polyribosome

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string of ribosomes simultaneously translating regions of the same mRNA strang durign protein synthesis

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gene mutation

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alteration in a gene due to a change in DNA composition

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transposon

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DNA sequence capable of randomly moving from one site to another in the genome

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genetic engineering

Back 23

alteration of genomes for medical or industrial purposes

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cloning

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production of identical copies; can be either the production of identical individuals or in genetic engineering, the production of identical copies of a gene

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gene cloning

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produdction of one or more copies of the same gene

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recombinant DNA

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DNA that contains genes from more than one source

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vector

Back 27

in genetic engineering, a means to transfer foreign genetic material into a cell

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plasmid

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self-duplicating ring of accessory DNA in the cytoplasm of bacteria

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restriction enzyme

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bacterial enzyme that stops viral reproduction by cleaving viral DNA; used to cut DNA at specific points during production of recombinant DNA

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DNA ligase

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enzyme that links DNA frangments; used during production of recombinant DNA to join foreign DNA to vector DNA

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polymerase chain reaction

Back 31

technique that uses the enzyme DNA polymerase to produce copies of a particular piece of DNA within a test tube

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DNA fingerprinting

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the use of DNA fragment lengths resulting from restriction enzyme cleavage to identify particular individuals

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Biotechnology

Back 33

term that encompasses genetic engineering and other techniques that make use of natural biological systems to create a product or achieve a particular result desired by humans

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trangenic organism

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free-living organism in the environment that has a foreign gene in its cells